This DTI is the relationship between a ‘stock’ (household debt levels) and a ‘flow’ (household incomes).

But it suffers from the same problem that “median multiples” suffer from. They are measuring an economic relationship, but not one that relates to how households actually assess their budgets.

The core affordability assessment is between take-home pay and the cost of making the regular payments (both ‘flows’). That is quite different to relating take-home pay to an asset price, or a total debt load.

Serviceability is the key here.

And the RBNZ’s data also includes that: “Servicing as % nominal disposable income” (sic).

So, what do we have here? It clearly shows 2016 serviceability at the same levels that existed in the decade plus between 1991 and 2003. The anomaly was 2004 to 2010.

This supports the idea that in 2017 household financial stress is not elevated.

This RBNZ data is not available regionally. Nor by income deciles. Both these aspects may well paint a different picture to the overall, national perspective.